1. Field
The following description relates to a hierarchical cell communication system, and more particularly, to a method and apparatus for determining a downlink transmit beamforming vector and a downlink receive beamforming vector for wireless communication.
2. Description of Related Art
Because of the variety of radio communication technologies and equipments, the demand for radio communication resources is rapidly increasing. This increase in demand results in a shortage of limited frequency resources. Therefore, there is a need for technology for more effectively using frequency resources.
A hierarchical cell environment indicates an environment in which small cells formed by small base stations within a macro cell are constructed as a self-organizing network form. Examples of a small cell include a relay cell, a femto cell, a pico cell, a cell by home node-B (HNB), a cell by home enhanced node-B (HeNB), a cell by remote radio head (RRH), and the like.
The hierarchical cell environment enables the total system capacity to increase. However, a quality of service (QoS) for a user may deteriorate because of interference between a macro base station and a small base station. Accordingly, there is a desire to effectively manage interference between a macro cell and a small cell.